The present invention relates generally to methods and apparatus for preventing electrostatic damage to and for cleaning a read/write (R/W) head of a tape drive. More particularly, the present invention relates to an improved tape head shutter mechanism that protects the R/W head from electrostatic discharge (ESD) damage. Also, as the leader buckle passes over the head, physical damage to the head can result. This is the case for MR (magneto-resistive) heads, ferrite heads and metal-in-gap (MIG) heads. This physical damage may not affect the read or write elements but can result in a shorter life of the tape.
Electrostatic discharge is a major concern in the use of R/W heads in tape drives. This is true of all R/W heads in general but is particularly true in the case of magneto-resistive (MR) heads, which are generally used in modern high density tape technology. In some tape drives, the leader, which is spliced to the tape on the cartridge and is used to connect the drive reel to the cartridge, builds up static charge from moving friction, thereby creating electrostatic discharge problems that would sometimes destroy the head when the leader comes in contact with it. Furthermore, the heads may sometimes be scratched by the leader material when the leader material is allowed to directly contact the head during tape operation.
To facilitate discussion, FIG. 1a is a diagrammatic top view representation of a R/W head 100 which is shown to be in moving contact with a tape/leader ribbon 102 traveling along the tape path. The tape/leader ribbon comprises of a leader segment 102a spliced onto a tape segment 102b. The leader segment is typically made of a conventional leader material, such as polyethylene terepthalate (PET) or another suitable leader material that is conventional in nature. The leader material tends to be stronger than tape and may, for example, have an approximate thickness of 0.007 in. in comparison with the tape thickness of 0.0005 in. As is well known, the leader serves the purpose of allowing the tape/leader ribbon to be taken up onto the drive reel so that the drive reel can be connected to the cartridge.
FIG. 1b is a diagrammatic side view representation of a tape/leader ribbon 104 traveling over a R/W head 106. Hidden lines 108 depict the part of the tape/leader ribbon that comes in contact with the R/W head and is blocked from view in the illustration of FIG. 1b.
The leader material is susceptible to charge accumulation, for example, when the cartridge made of a non-conductive material is removed from the tape drive and comes in contact with other surfaces. The accumulated electrostatic charge may discharge through the R/W head, thereby causing severe damage to the R/W head. In particular, MR heads are found to be especially vulnerable to ESD damage.
In view of the foregoing, what is desired is a method and an apparatus for protecting the R/W head during tape operation. More particularly, what is desired is a method and an apparatus for protecting the R/W head from electrostatic discharge damage and physical damage that is caused by moving contact between the R/W head and the tape leader material.